For some people, the start of September means it's back to school time. For others it's a reminder of how short Massachusetts summers are. Yet for those of us who love spectacular natural phenomena, September marks the beginning of the official hawk migration season.
Birds of prey eat a wide variety of animals, ranging in size from grasshoppers to deer carcasses. Some of those animals become hard to find in the winter. Insects are dormant in one of their metamorphic stages. Small rodents hide in tunnels under the snow. Weasels and snowshoe hare turn white and vanish against the snowy back drop of winter. Fish live safely in their watery home protected by a roof of ice.
So the raptors that feed on these creatures must go to warmer places where food is still abundant.
Unlike many of the songbirds which make their southbound journey at night, hawks fly when we can easily watch them. They follow predictable routes, using noticeable weather patterns, and often gather in large numbers. All of these elements make hawk watching something that beginners and experts alike can get excited about at this time of year.
One thing that makes hawk watching accessible is that raptors are relatively large (although they can look like specks when they are extremely high up), and there are only about a dozen species that are likely to be seen in our area. So learning to identify them is not as hard as with some other avian groups.
Hawks are classified into three major categories, each with its own characteristic shape and behaviors. Accipiters are woodland hawks with short wings and a long tail. Buteos are true soaring hawks of open country. They have wide wings and shorter fan-shaped tails. Falcons have narrow tails and pointy wings that help them dart fast in pursuit of other birds.
Additional plumage variations and size distinguish the three or four species within these groups. Eagles, ospreys, vultures and northern harriers offer interesting additions to the list of birds on the move and bring added excitement when they are seen.
Timing can also provide tips for identification as species move according to different schedules. The broad-winged hawks are most often seen during the middle of September.
Ospreys are more common later in September and early October.
Northern goshawks bring up the rear and move during the second half of October.
Sharp-shinned hawks however can be reliably seen throughout the fall.
Birders identifying and count individuals and groups of birds at prominent places throughout the autumn. Many of these inventories are sent to the Hawk Migration Association of North America and combined with sightings from across the continent. The accumulated information provides a valuable picture of how these birds are doing over time and space. So not only is hawk watching fun -- it provides important data.
Not everyone gets excited about tallying dozens of tiny flying specks on a chilly fall day. But something that could excite even the most electronically focused couch potato is witnessing a swirling "kettle" of hundreds of broad-winged hawks as they rise into the sky on columns of warm air called thermals.
Like ascending on an elevator, the "broadwings" conserve energy and let the thermals take them up and nearly out of sight. Then they peel off the top of the thermal and soar in a southerly direction, descending as they go and aiming for another thermal so they can repeat the pattern.
Using this technique they can travel great distances by hardly flapping a wing.
When the conditions are right -- a clear day after a spell of rain, with a gentle breeze from the north, and warming temperatures -- a hawk watcher can witness more than a thousand hawks in one day.
If you go ...
The best way to learn more about hawk migration and witness this fall ritual, is to go to a hawk-watch site and spend time with regulars.
In the Berkshires, Mount Greylock in North Adams and Mount Everett in Egremont are notable places.
Here's one field trip coming up this weekend.
What: Blueberry Hill Hawk Watch -- look for raptors overhead and migrating passerines in the woods.
Where: Bring a dish to share and meet Tom Begley at Price Chopper parking lot on Pittsfield-Lenox Road to carpool
When: Saturday, 7:30 a.m.
Rain date Sunday
Information: (413) 655-0112
Or visit the Mass Audubon website for more general information: